> ## Documentation Index > Fetch the complete documentation index at: https://cosmos-docs-sync-security-docs.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # broadcast_tx_sync > Returns with the response from CheckTx. Does not wait for DeliverTx result. If you want to be sure that the transaction is included in a block, you can subscribe for the result using JSONRPC via a websocket. See https://docs.cosmos.network/cometbft/v0.38/docs/core/Subscribing-to-events-via-Websocket If you haven't received anything after a couple of blocks, resend it. If the same happens again, send it to some other node. A few reasons why it could happen: 1. malicious node can drop or pretend it had committed your tx 2. malicious proposer (not necessary the one you're communicating with) can drop transactions, which might become valid in the future (https://github.com/tendermint/tendermint/issues/3322) Please refer to [formatting/encoding rules](https://docs.cosmos.network/cometbft/v0.38/docs/core/Using-CometBFT#formatting) for additional details ## OpenAPI ````yaml /cometbft/latest/api-reference/rpc/openapi.yaml get /broadcast_tx_sync openapi: 3.0.0 info: title: CometBFT RPC contact: name: CometBFT url: https://docs.cosmos.network/cometbft description: > CometBFT supports the following RPC protocols: * URI over HTTP * JSONRPC over HTTP * JSONRPC over websockets ## Configuration RPC can be configured by tuning parameters under `[rpc]` table in the `$CMTHOME/config/config.toml` file or by using the `--rpc.X` command-line flags. The default RPC listen address is `tcp://127.0.0.1:26657`. To set another address, set the `laddr` config parameter to desired value. CORS (Cross-Origin Resource Sharing) can be enabled by setting `cors_allowed_origins`, `cors_allowed_methods`, `cors_allowed_headers` config parameters. If testing using a local RPC node, under the `[rpc]` section change the `cors_allowed_origins` property, please add the URL of the site where this OpenAPI document is running, for example: `cors_allowed_origins = ["http://localhost:8088"]` or if testing from the official documentation site: `cors_allowed_origins = ["https://docs.cosmos.network"]` ## Arguments Arguments which expect strings or byte arrays may be passed as quoted strings, like `"abc"` or as `0x`-prefixed strings, like `0x616263`. ## URI/HTTP A REST like interface. curl localhost:26657/block?height=5 ## JSONRPC/HTTP JSONRPC requests can be POST'd to the root RPC endpoint via HTTP. curl --header "Content-Type: application/json" --request POST --data '{"method": "block", "params": ["5"], "id": 1}' localhost:26657 ## JSONRPC/websockets JSONRPC requests can be also made via websocket. The websocket endpoint is at `/websocket`, e.g. `localhost:26657/websocket`. Asynchronous RPC functions like event `subscribe` and `unsubscribe` are only available via websockets. For example using the [websocat](https://github.com/vi/websocat) tool, you can subscribe for 'NewBlock` events with the following command: echo '{ "jsonrpc": "2.0","method": "subscribe","id": 0,"params": {"query": "tm.event='"'NewBlock'"'"} }' | websocat -n -t ws://127.0.0.1:26657/websocket version: v0.38.x license: name: Apache 2.0 url: https://github.com/cometbft/cometbft/blob/v0.38.x/LICENSE servers: - url: https://rpc.cosmos.directory/cosmoshub description: Interact with the CometBFT RPC from a public node in the Cosmos registry - url: http://localhost:26657 description: Interact with CometBFT RPC node running locally security: [] tags: - name: Info description: Informations about the node APIs - name: Tx description: Transactions broadcast APIs - name: ABCI description: ABCI APIs - name: Evidence description: Evidence APIs - name: Unsafe description: Unsafe APIs paths: /broadcast_tx_sync: get: tags: - Tx summary: broadcast_tx_sync description: >- Returns with the response from CheckTx. Does not wait for DeliverTx result. If you want to be sure that the transaction is included in a block, you can subscribe for the result using JSONRPC via a websocket. See https://docs.cosmos.network/cometbft/v0.38/docs/core/Subscribing-to-events-via-Websocket If you haven't received anything after a couple of blocks, resend it. If the same happens again, send it to some other node. A few reasons why it could happen: 1. malicious node can drop or pretend it had committed your tx 2. malicious proposer (not necessary the one you're communicating with) can drop transactions, which might become valid in the future (https://github.com/tendermint/tendermint/issues/3322) Please refer to [formatting/encoding rules](https://docs.cosmos.network/cometbft/v0.38/docs/core/Using-CometBFT#formatting) for additional details operationId: broadcast_tx_sync parameters: - in: query name: tx required: true schema: type: string example: '456' description: The transaction responses: '200': description: Empty content: application/json: schema: $ref: '#/components/schemas/BroadcastTxResponse' '500': description: Error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' components: schemas: BroadcastTxResponse: type: object required: - jsonrpc - id - result - error properties: jsonrpc: type: string example: '2.0' id: type: integer example: 0 result: required: - code - data - log - hash properties: code: type: string example: '0' data: type: string example: '' log: type: string example: '' codespace: type: string example: ibc hash: type: string example: 0D33F2F03A5234F38706E43004489E061AC40A2E type: object error: type: string example: '' ErrorResponse: description: Error Response allOf: - $ref: '#/components/schemas/JSONRPC' - type: object properties: error: type: string example: Description of failure JSONRPC: type: object properties: id: type: integer example: 0 jsonrpc: type: string example: '2.0' ````